1. Field of the Invention
The present invention relates to a portion tobacco product in which a tobacco filler is included in a pouch comprising a wrapping material having a function of controlling the permeation of a compound contained in the tobacco filler.
2. Description of the Related Art
Smokeless tobacco products such as moist-snuff or snuffs have attracted attention in recent years. These include a portion tobacco product in which a tobacco filler containing leaf tobacco shreds is wrapped in a pouch composed of a nonwoven fabric of cellulose fibers or the like. One can enjoy the taste and flavor derived from the leaf tobacco shreds of such a portion tobacco by putting it into the gap between the lip and gum in the mouth (U.S. Patent Application Publication No. 2007/062549).
In enjoying the taste and flavor derived from the leaf tobacco shreds of such a portion tobacco product, a leaf tobacco shred component or a component added to the shreds is eluted from the pouch into the saliva without being controlled, and may adversely affect the taste and flavor. Furthermore, the product comprising a tobacco filler that is wrapped in a pouch composed of a nonwoven fabric or the like is shipped in a state that the tobacco filler has been adjusted to have a constant water content; however, a colorant compound is eluted from the leaf tobacco shreds over time, and a visually unpleasant blot such as a spot occurs on the surface of the pouch in some cases. Furthermore, when such a product is put into the mouth according to a general usage, the tobacco filler gets wet by the moisture in the mouth, and thus the colorant compound derived from the leaf tobacco shreds is eluted, thereby the gum and skin in the mouth are stained in some cases.
U.S. Pat. No. 6,162,516 describes an impermeable sheet for preventing snuff from direct contact with the skin in the mouth. However, this sheet cannot prevent the colorant compound contained in the leaf tobacco shreds from causing staining of the pouch, and the colorant compound may be eluted into the saliva in the mouth. In such a case, this sheet cannot prevent the contact of the colorant compound with the skin in the mouth.
U.S. Pat. No. 5,077,104 does not disclose a portion tobacco product, but describes a nicotine-sealed pouch comprising a nicotine barrier layer containing a nitrile rubber-modified acrylonitrile-methyl acrylate copolymer and a nicotine degradation agent barrier layer. This pouch controls the transfer of a component by a substance that has a property of adsorbing nicotine (for example, a nitrilated acrylonitrile vinyl). Therefore, even if leaf tobacco shreds are applied to the pouch of this literature, the elution of substances other than nicotine cannot be suppressed, although the maintenance and control of elution of nicotine are possible.